Thirty-seven eyes of 37 individuals without eye diseases were included in this study. Optical Coherence Tomography (OCT) images were taken using Cirrus HD-OCT (Carl Zeiss Meditec) with 5 line raster and high-definition 5 line raster modes. Images with signal strength weaker than 5/10 were excluded. Distinction of COST line and the integrity of COST line, external limiting membrane, and the photoreceptor inner segment and outer segment junction at the fovea were recorded. Demographic data, refractive error of the eyes, signal strengths of the OCT images were acquired for analysis.